What happened

Shares of Citius Pharmaceuticals (CTXR -3.86%), a clinical-stage biopharmaceutical company, are getting beaten down today after the company released disappointing news regarding its lead candidate, Mino-Lok. Investors, worried that the treatment isn't going anywhere fast, dragged the stock 19.8% lower as of 12:10 p.m. EDT on Thursday.

So what 

Throughout most of June, Citius Pharmaceuticals stock climbed in anticipation of the third planned interim analysis of a phase 3 trial with Mino-Lok. This is an antibiotic lock solution that could be used to salvage central line catheters that become infected. 

Three people in white lab coats looking at a tablet.

Image source: Getty Images.

All the way back in February of 2018, Citius began the 144-patient phase 3 trial comparing Mino-Lock to standard antibiotics. Investigators are measuring the length of time before catheter failure events to see if Mino-Lok is superior. The stock is tanking today because the third interim analysis scheduled for June 29 didn't find evidence of superiority.

Citius waited until today to tell investors that everything is fine in a press release. According to the company, Mino-Lok hasn't achieved superiority over standard care yet, but it might be possible if the company simply finishes the study as planned.

Now what

Citius has been running the phase 3 Mino-Lok trial for more than three years in 25 hospitals spread throughout the U.S. That's more than enough time to find 144 people with central line infections, but the company still hasn't finished with enrollment.

Slow enrollment doesn't necessarily mean an experimental new drug isn't going to work. That said, start-up drugmakers with experimental treatments that eventually succeed tend to work much faster than Citius.

In the unlikely event that the final analysis of the phase 3 trial with Mino-Lok shows evidence of superiority, Citius Pharmaceuticals still faces an uphill battle. There aren't any Food and Drug Administration-approved antibiotic lock solutions for preserving infected central line catheters because getting hospitals to pay for one will be impossible without clear evidence of superiority. 

If Citius Pharmaceuticals hasn't been able to provide evidence of superiority after running a multisite phase 3 trial for over three years, it probably isn't going to happen.